1. Field of the Invention
The technical scope of the invention is that of sub-caliber projectiles of the fin-stabilized type and more particularly shape matching linking means for the sabot and penetrator of such a projectile.
2. Description of the Related Art
The sabot and penetrator are generally linked together by threading, and more rarely by circular grooves.
The sabot thus incorporates a first profile machined at its bore, such profile cooperating with a second profile on the penetrator.
In any event, if a longitudinal section of the projectile is considered, each profile has a shape that alternates teeth and grooves.
It is classical to provide constant play between teeth and grooves, such play normally enables the penetrator to be screwed on when the profile are threads. This play is generally enough to enable differential dilations between the sabot (maid of several segments) and the penetrator. Indeed, the materials used for the sabot and the penetrator are very different (more often than not aluminum for the sabot and tungsten alloy for the penetrator) and also have different dilatation coefficients.
So as to enable such differential dilatations, without this resulting in a spacing of the sabot segments that would hinder the projectile's being positioned in the weapon chamber, patent FR2628196 proposes to produce threading that has a different pitch for the front and rear flanks of the threads. Such an arrangement further enables the relative axial position of the penetrator with respect to the sabot to be controlled whilst enabling differential dilatations.
Such a solution is not satisfactory, however, for present-day projectiles in which the penetrator is very long (over 700 mm). Indeed, in this case the interface between the sabot and the penetrator is also long (greater than or equal to 300 mm). However, with known solutions described by FR2628196, the support between the sabot and penetrator is made at a front part of the sabot. Because of the length of the interface, the differential dilatations become too great and the differential threading leads to the production of teeth that are too small to withstand the firing constraints.